1. Field of the Invention
The invention relates to a terminal fitting and to a method of producing it.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2011-238372 discloses a terminal fitting with a tubular connecting portion and a spring piece resiliently deformably arranged in the connecting portion. The connecting portion includes a base wall in the form of a flat plate extending in forward and backward directions and side walls standing up from opposite widthwise ends of the base wall. The spring piece is folded backward from the front end of the base wall and resiliently deformed toward the base wall when a tab of a mating terminal fitting inserted into the connecting portion comes into contact therewith. Further, cuts are made in the both side walls and cut portions are bent to project into the connecting portion, thereby forming excessive deformation preventing pieces. The spring piece is prevented from being excessively resiliently deformed by coming into contact with the excessive deformation preventing pieces.
Distances from the both side walls to the spring piece become longer, for example, if the width of the spring piece is smaller than that of the base wall. Thus, the projection amounts of the excessive deformation preventing pieces become larger and it becomes difficult to ensure a space for forming the excessive deformation preventing pieces on the both side walls by cutting and bending.
Further, in the above conventional configuration, the spring piece may be warped and deformed into a U shape so that a widthwise central portion drops toward the base wall with the opposite widthwise ends held in contact with the excessive deformation preventing pieces as supporting points.
In view of the above situation, it is also possible to form excessive deformation preventing pieces on the base wall. However, for example, when the spring piece is divided into a first spring piece and a second spring piece and the second sprint piece is provided on the base wall, there is a problem of being difficult to ensure a space for arranging the excessive deformation preventing pieces on the base wall.
Japanese Unexamined Patent Publication No. 2004-362832 discloses a terminal fitting with a tubular main portion and a resilient piece resiliently deformably arranged in the main portion. The resilient piece is in the form of a tongue piece extending backward in a cantilever manner from an arcuate supporting point portion connected to the front end of the main portion. A male tab of a mating terminal fitting is inserted into the main portion from front. The inserted male tab resiliently comes into contact with the resilient piece, whereby both terminal fittings are electrically connected.
If the resilient piece is narrow when the male tab is wide, the resilient piece cannot stably support the male tab and the male tab may be inclined such as by rolling about an axis.
On the other hand, if the resilient piece is made wider in conformity with the size of the male tab, a resilient reaction force applied to the male tab from the resilient piece becomes excessive and insertion operability of the male tab may be deteriorated. Contrary to this, if the resilient reaction force is reduced, such as by cutting the supporting point portion of the resilient piece, the male tab cannot be stably supported and may be inclined about the axis as in the above case.
Japanese Unexamined Patent Publication No. 2009-48831 discloses a terminal fitting with includes a rectangular tube which can come into contact with a tab portion of a male terminal fitting. The rectangular tube is composed of a bottom plate, a pair of side plates standing up from opposite side edges of the bottom plate, a ceiling plate bent at the upper end edge of one side plate and extending toward the other side plate and a pressing portion bent at the upper end edge of the other side plate and configured to prevent the opening of the ceiling plate by pressing the upper surface of the ceiling plate.
However, this configuration is not preferable in reducing the height of the terminal fitting since the pressing portion is placed on the ceiling plate and projects upward from the ceiling plate. As a countermeasure, it is thought to form a recessed area in the ceiling plate and place the pressing portion in this recessed area.
The following problem needs to be solved even if the above countermeasure is taken. Specifically, if the recessed area of the ceiling plate is formed by press working, a peripheral edge part in the recessed area generally becomes a moderately arcuate surface (R-surface). Thus, the pressing portion has to be arranged in a part of the recessed area inside the peripheral edge part while avoiding the peripheral edge part which is the R-surface. Then, a gap is formed between the peripheral edge of the recessed area and the end edge of the pressing portion.
On the other hand, in the process of inserting the terminal fitting into a cavity of a connector housing, a locking lance formed in the cavity slides in contact with the outer surface of the rectangular tube portion while being resiliently deformed. Thus, if the above gap is located on this slide contact path, the locking lance may drop into the gap and be caught by the end edge of the pressing portion, with the result that smooth insertion of the terminal fitting may be obstructed.
Japanese Unexamined Patent Publication No. 2004-206912 discloses a female terminal fitting with a rectangular tube composed of a bottom plate, a pair of side plates standing up from opposite side edges of the bottom plate and a pair of ceiling walls bent from the rising end edges of the both side plates. A leading end part of one of the both ceiling walls is bent downwardly to form a step, and a leading end part of the other ceiling wall is placed on this step part. A locking hole is formed in the step part. By fitting a locking piece formed by bending the leading end part of the other ceiling wall into this locking hole, the ceiling walls are prevented from being displaced in forward and backward directions.
However, the following problem needs to be solved in the case of adopting a displacement prevention structure as described above. Specifically, the locking piece projects outwardly from an end edge of the ceiling wall in the above female terminal fitting, which is not preferable in cutting layout.
The present invention was completed in view of the above situation and an object thereof is to improve overall operability and space efficiency.